Summary The Wamair Service Outfitting Inc. Piper PA-31-350 Chieftain aircraft (registration C-GRNK, serial number 31-7652112) was departing Matheson Island, Manitoba, on a visual flight rules flight to Poplar River, Manitoba, with one pilot and seven passengers on board. Shortly after lift-off, the pilot noted indications of right-engine power loss. The pilot secured the engine and turned the aircraft to return to the Matheson Island aerodrome. The aircraft did not gain altitude, and the pilot carried out a forced landing in a marsh approximately two nautical miles southwest of the aerodrome. The pilot and passengers exited the aircraft and were taken by boat to the nearest road and from there by ambulance to medical facilities. The aircraft sustained substantial damage. There was no post-crash fire. The accident occurred during daylight hours at 1800central daylight time. Ce rapport est galement disponible en franais. Other Factual Information The observed weather at 1800 central daylight time1 at Winnipeg, Manitoba, 110nautical miles (nm) south of Matheson Island, was as follows: wind 320true(T) at 12knots gusting to 18knots, visibility 15statute miles, with a few towering cumulus clouds at 5100feet. The 1700temperature was 18C and dewpoint was 13C. The observed weather at 1800at Berens River, 38nm north of Matheson Island, was as follows: temperature 18C, winds north-northeast at 4knots. The winds at Matheson Island were estimated as northwest at 10knots gusting to 18knots. The pilot held a commercial pilot licence endorsed for single- and multi-engine land and sea aeroplanes. The licence was validated by a medical certificate valid to December2007. The pilot's last pilot proficiency check was completed on 01June2007 and was valid to July2009. Maintenance records indicated that the aircraft was equipped and maintained in accordance with the current Canadian Aviation Regulations (CARs). The aircraft had been modified in 1995by the incorporation of a Boundary Layer Research, Inc. Super ChieftainI gross weight increase kit. The modification consisted of engine nacelle strakes and 88vortex generator tabs affixed to the wings and vertical tail. The United States Federal Aviation Administration (FAA) approval of the modification required that a minimum of 84vortex generator tabs be present on the aircraft. The modification increased the maximum approved gross take-off weight of the aircraft from 7000pounds to 7368pounds. The modification revised the centre of gravity limits to 126to 135inches aft of datum, at a gross weight of 7000pounds. With the modification, the aircraft's minimum single-engine control speed is revised to 72knots and the single-engine best rate of climb speed is 107knots. The aircraft load at take-off consisted of a pilot, seven passengers, baggage, and fuel. The aircraft's load was recalculated by TSB investigators using actual passenger weights. The recalculation indicated that the aircraft's gross weight at take-off was 6978pounds and the centre of gravity was between 133and 134.2inches aft of datum. The pilot conducted a passenger briefing before departure. During the briefing, the pilot mentioned that seat belts were to be worn during the flight. Two of the passengers required seat-belt extensions in order to use the aircraft's seat belts. There was only one seat-belt extension on board. One passenger did not use the seat belt at any time during the flight. The CARss require that aircraft be equipped with a seat belt for each person on board, that passengers comply with crew instructions to secure seat belts, and that all passengers be seated and secured.2 Matheson Island is a registered aerodrome, elevation 725feet, with one gravel-surfaced runway 3500feet long, oriented 028 to 208 magnetic(M) (Runways03 and21). Take-off from Matheson Island in the direction of Poplar River requires over-water operation, some of which is likely beyond gliding distance from land. No over-water equipment was noted in the aircraft during a post-occurrence examination. The operator recently increased the clearway past the north end of the runway to about 1200feet. On departure, the pilot taxied the aircraft to the south end of the runway and conducted a rolling take-off (to prevent propeller damage) on Runway03 with a flap setting of 15. The pilot set engine power to maximum (2575)rpm and 42inches of manifold pressure, in accordance with his training, and rotated the aircraft near the departure end of Runway03 at about 72knots; the landing gear and flaps were raised shortly thereafter. Almost immediately after lift-off, the right engine began to lose power and trail black smoke. The pilot initially attributed the changing control forces resulting from the power loss to windshear resulting from crosswind over the trees upwind of the runway. Once the aircraft was above the trees, the pilot identified the power loss, shut down the engine and feathered the propeller. The aircraft attained an airspeed of 90to 100knots, did not accelerate, and did not climb above its initial altitude of about 200feet above ground level (agl) during the remainder of the flight. The pilot made a brief radio transmission as to the situation, and then turned the aircraft to the left to initiate a race track circuit to return to Runway03. He chose this procedure in order to land into wind and avoid a 180 return to Runway21. During the power loss recovery procedure, the pilot initially increased manifold pressure up to the maximum allowed 49inches, but then reduced power in order to maintain directional control. Aircraft performance is reduced in a turn. During the turn from downwind to base leg, the aircraft lost altitude. The pilot prepared for a forced landing and called for the passengers to prepare to brace for the impact. The aircraft landed in a marshy area with shallow water and tall reeds. The pilot landed with the landing gear retracted and the flaps up. Landing with the landing gear retracted reduces the risk that the aircraft will overturn in a landing on a soft surface. Landing with the flaps retracted maximizes the aircraft performance during the approach, and tends to lead to a somewhat nose-high attitude on landing, which reduces the risk that the nose will dig into a soft surface and the aircraft will overturn. After the aircraft came to rest, the pilot initiated a passenger evacuation onto the aircraft wings, when water started to enter the passenger compartment. Some passengers suffered various non-life-threatening injuries as a result of the bumpy landing. Most passengers, including the passenger without a seat belt, were mobile and were able to leave the aircraft unassisted. Several Wamair Service Outfitting Inc. staff members responded to the occurrence with vehicles and boats to transport the aircraft occupants to the nearest road, about 0.3nm from the aircraft's position in the marsh. The passengers were taken by ambulance for medical attention. One passenger had suffered serious injuries. The pilot and three passengers had sustained minor injuries. Three passengers were not injured. The aircraft's approved aircraft flight manual (AFM) Procedures Section indicates that the take-off procedure is, in part, throttles- full forward,7 and then manifold pressure (43inch normal-static sea level, standard temperature 15C)- checked. The AFM Limitations Section indicates that each engine is rated to produce 350HP at 2575rpm. The maximum allowed manifold pressure below 15000feet is 49inches. The single-engine climb performance chart in the AFM is based on one engine feathered and a functioning-engine power setting of 2575rpm and full throttle. The Operating Tips Section appended to the AFM indicates that Normal take-off manifold pressure is approximately 43to 44inches (sea level std. temperatures). The AFM emergency procedure for an engine failure during short-field take-off below 106knots specifies that the engine should be shut down, the fuel and ignition turned off, and the aircraft should be landed avoiding obstacles. The AFM specifies the following for speeds above 106knots: maintain directional control power - maximum continuous on the operating engine feather the propeller on the inoperative engine bank 5 into the operating engine; and airspeed, maintain 106knots until clear of obstacles and then maintain 109knots. It does not provide an emergency procedure to deal specifically with a malfunction of the turbocharger. The manufacturer of the engine (Lycoming LTIO-540-J2BD) has produced a power setting chart to assist maintenance engineers when setting up the engine for correct operation. The chart (Lycoming Service Instruction 1187J) indicates a normal setting of 42.2to 46.7inches, depending on compressor discharge temperature. The chart's procedures are designed to allow the engine to automatically provide a minimum of 350HP at full throttle, at various combinations of temperature and pressure. The aircraft manufacturer advised that 43inches of manifold pressure and 2575rpm would yield 350HP at sea level and 15C, and that greater manifold pressure would be required, and would be automatically provided, at higher temperatures and altitudes. The operator was using a quick reference handbook (QRH) compiled by another aircraft operator, obtained from that operator when the aircraft was purchased by Wamair Service Outfitting Inc. The QRH listed various procedures and limitations, including a take-off power setting of 2575rpm and 37to 42inches of manifold pressure. The QRH was not approved by Transport Canada for Wamair Service Outfitting Inc.'s operation, and it does not supersede the AFM. The aircraft was not equipped with flight data or cockpit voice recorders, nor were such recorders required by regulation. The certification basis of the aircraft does not require the aircraft to be capable of a positive rate of climb in the event of an engine failure. There is no requirement for the aircraft to meet engine-inoperative accelerate-stop or accelerate-go performance specifications. The aircraft performance charts indicate that the aircraft's take-off distance, at maximum rated power, and the aircraft weight and atmospheric conditions applicable to the accident aircraft should be about 1500feet, and that the aircraft should be capable of a positive single-engine rate of climb of about 190feet per minute at best rate of climb airspeed. Take-off performance is predicated on a paved, level, dry surface and full power set before beginning the take-off roll. No performance charts were available for rolling take-offs or for take-off performance from gravel runways, although these conditions are known to increase aircraft take-off distances. The aircraft was recovered from the marsh and was examined by TSB investigators. No structural or control anomalies were noted. The right engine was removed for examination. The engine had been overhauled in February2003 at a total accumulated flight time of 1997hours. The engine had been repaired in November2005 and December2006 at accumulated times of 624and 820hours, respectively. The engine could not be run because of internal corrosion resulting from submersion in water during the occurrence. The aircraft's fuel and fuel delivery system was examined to the extent possible. Several parts of the system had been damaged during the forced landing. However, the aircraft's fuel tanks contained sufficient fuel for the intended flight and no anomalies were noted. The engine's spark plugs were black and sooty. The right engine's turbocharger system was examined. The differential pressure controller was removed and disassembled. The adjustment of the controller was checked by attempting to turn the poppet valve. The valve is held in place by a threaded shaft and is normally secured by fibre sealant. The valve was found to turn so easily on its shaft that the security of its adjustment was not assured. Oil was found on the air side of the valve, and its adjustment was found at the upper limit of its allowable range. The controller incorporates a rubber bellows diaphragm, which was also tested. It was found to leak air from a hole, and was loose on its base. As a result, it bypassed air and failed the test. The combination of the poppet valve setting and the loose and defective diaphragm would have signalled the engine's turbocharger waste gate to open and drop the turbocharger off line. Records indicated that the differential pressure controller was overhauled with the engine in February2003 and had been repaired in September2004 at an accumulated time of 350hours. The engine's turbocharger system is designed to provide positive air pressure to the engine's intake manifold, up to the maximum prescribed limit. The air pressure is provided automatically, in response to scheduled fuel, as controlled by throttle input. The pilot controls throttle setting, and as the throttle setting is increased, the turbocharger comes on line to an increasing extent to provide sufficient air to maintain an efficient mixture of fuel and air in the intake manifold, and from there, into the cylinders. If the turbocharger drops off line, the volume of fuel delivered to the engine intake manifold will continue unchanged at a given rpm. However, the volume of air will be drastically reduced at higher power settings because the engine no longer receives pressurized air, and must draw it through the intake system past the non-functioning turbocharger. As a result, the manifold pressure drops and the fuel-air mixture in the engine becomes significantly richer and may become too rich for the engine to burn, resulting in a loss of engine power.